Screw-propeller



(No Model.)

P. STAUGIL Jr. SCREW PROPBLLBR.

N9. 471,907. Patent ed Mar.29,1892.

UNITED STATES PATENT OFFICE.

PHILIP STAUCH, JR, OF CHICAGO, ILLINOIS.

SCREW-PROPELLER.

SPECIFICATION forming part of Letters Patent No. 471,907, dated March29, 1892. Application filed April 28, 1890. Serial No- 349,816. (Nomodel.)

To all whom it may concern- Be it known that I, PHILIP STAUCH, J12, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Screw-Propellers; and I do declare the following to be a full, clear,and eX- act description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, which form a part of this specification.

My invention relates to screw-propellers for steamboats, and has for itsobject the overcoming of the loss of energy due to thelateraldisplacement of water in propellers of this class.

In the accompanying drawings, Figure 1 shows a side view of mypropeller; Fig. 2, an end view, and Fig. 3 a section of one of .theblades.

Two sets of blades are used, the blades A for forward propulsion, B forbacking the vessel. I

The novelty of the device consists in the form of the blades. Thecutting side a of the blade A is flat and offers the minimum ofresistance, its edge lying in the plane of its revolution. The oppositeside a is concave like'the bowl of a spoon, terminating in a curved tip.The curvature is sufficient to bring the edge and tip in the samedirection as the shaft 0, which carries the blades. The efiect upon thewater is to force it in a-straight line back from the boat, so that theentire reaction is communicated to the vessel exactly in the directionof her'forward movement. The blades are set upon the shaft at an angleof about forty-five degrees, their efiectiveness being thus greatlyincreased. The form of blade described is inoperative when reversed, anda second series Bis placed upon the shaft immediately forward of theblades A and in exactly the reverse position for the purpose of backingthe vessel. As shown, the two series of blades are carried upon the sameshaft, so that whichever the direction of revolution one series isefiective and the other is not. A decided advantage may be secured inefficiency, though at an increased cost of construction, by attachingthe blade B to a hollow shaft and the blades A upon an independent solidshaft working within it, so that the screws may be turned separately.

I claim- A screw-propeller having two sets of blades inclined,respectively, backward and forward from the perpendicular, each bladehaving one of its edges directed in the plane of its rotary movement andits opposite edge directed in a plane parallel with the axis of thescrew, the concave surface of the several blades being in the directionof their inclination, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

PHILIP STAUCH, JR.

Witnesses:

F. M. HUNTER, Mo. 0. WEBER.

